Photon-efficient quantum key distribution using time–energy entanglement with high-dimensional encoding
Name
Zhong-2015-Photon-efficient qua.pdf
Size
1.4 MB
Format
Adobe PDF
Checksum (MD5)
7db84e7787451f24b5e3c15f9bbc38e5
Author(s)
Zhong, Tian
Zhou, Hongchao
Horansky, Robert D.
Lee, Catherine
Verma, Varun B.
Lita, Adriana E.
Restelli, Alessandro
Bienfang, Joshua C.
Mirin, Richard P.
Gerrits, Thomas
Date Issued
February 2015
Journal
New Journal of Physics
Publisher
IOP Publishing
Citation
Zhong, Tian, Hongchao Zhou, Robert D Horansky, Catherine Lee, Varun B Verma, Adriana E Lita, Alessandro Restelli, et al. “Photon-Efficient Quantum Key Distribution Using Time–energy Entanglement with High-Dimensional Encoding.” New Journal of Physics 17, no. 2 (February 1, 2015): 022002. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
Version
Final published version
Abstract
Conventional quantum key distribution (QKD) typically uses binary encoding based on photon polarization or time-bin degrees of freedom and achieves a key capacity of at most one bit per photon. Under photon-starved conditions the rate of detection events is much lower than the photon generation rate, because of losses in long distance propagation and the relatively long recovery times of available single-photon detectors. Multi-bit encoding in the photon arrival times can be beneficial in such photon-starved situations. Recent security proofs indicate high-dimensional encoding in the photon arrival times is robust and can be implemented to yield high secure throughput. In this work we demonstrate entanglement-based QKD with high-dimensional encoding whose security against collective Gaussian attacks is provided by a high-visibility Franson interferometer. We achieve unprecedented key capacity and throughput for an entanglement-based QKD system because of four principal factors: Franson interferometry that does not degrade with loss; error correction coding that can tolerate high error rates; optimized time–energy entanglement generation; and highly efficient WSi superconducting nanowire single-photon detectors. The secure key capacity yields as much as 8.7 bits per coincidence. When optimized for throughput we observe a secure key rate of 2.7 Mbit s[superscript −1] after 20 km fiber transmission with a key capacity of 6.9 bits per photon coincidence. Our results demonstrate a viable approach to high-rate QKD using practical photonic entanglement and single-photon detection technologies.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology. Research Laboratory of Electronics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/1367-2630/17/2/022002
